In image display units such as monitors of television set and office automation system, in order to prevent or decrease surface reflection, an antireflection film is provided on an image plane of image display units (for example, International Patent Publication WO 02/18457).
However an antireflection film has a very thin thickness of 0.03 to 0.5 μm to secure transparency, and a surface sliding property thereof is not good (a friction coefficient is high). Therefore there is a case where the film is damaged or peeled by wiping off stains on its surface repeatedly.
For improving surface sliding property, there is generally known a method of applying a liquid water- and oil-repellent agent such as a low molecular weight silicone oil or a fluorine-containing oil or a method of admixing a liquid water- and oil-repellent agent. However there is no long-lasting effect of the agent.
Also there is proposed a method of improving surface sliding property by applying a polymer (for example, JP10-287719A). JP10-287719A says that according to the method proposed therein, a friction coefficient of a surface of a substrate such as glass can be decreased, abrasion resistance can be given to the surface, a surface hardness can be increased, a water contact angle can be increased, and chemical resistance can be enhanced by applying, on the substrate, a hydrogen-containing polymer modified by fluorination, which is obtained by polycondensation reaction, polyaddition reaction or graft-reaction of a hydrogen-containing monomer or polymer (for example, polyurethane, polyacrylate or the like) with a fluorination modifier having a perfluoropolyether structure represented by the formula:RfO(CF2CF2O)m(CF2O)nCF2-Aq-Tp wherein Rf is a perfluoroalkyl group having 1 to 3 carbon atoms; A is a crosslinkable group bonded to an end of —CF2— (a bond such as an alkylene group or an oxyalkylene group but not a crosslinkable functional group); T is a reactive functional group, and then carrying out UV crosslinking or peroxide crosslinking.
However the hydrogen-containing polymer modified by fluorination, which is disclosed in JP10-287719A is synthesized by reacting a fluorination modifier with a hydrogen-containing polymer on a substrate surface when forming a thin film. Further this fluorination modifier, particularly a fluorination modifier having a highly fluorinated long chain fluoropolyether structure being excellent in stain-proofing property and sliding property is soluble in fluorine-containing solvents but is insufficient in solubility in general purpose solvents. Therefore a fluorine-containing solvent is required in synthesizing and coating steps, which results in high cost and much burden on environment.
The present inventors made intensive studies to develop a surface modifier which improves surface sliding property, is soluble in non-fluorine-containing general purpose solvents and makes it easy to form a thin film, and completed the present invention.